This invention relates to a vaccine capable of stimulating the immune response of a tumorous mammal against mammalian tumors, and, in particular, against species-specific mammalian tumors. Species-specific tumors are those which are specific to a particular species of mammal. The tumors may be induced, as can be the BALB/C male mouse peritoneal macrophage tumor, designated GMMSVI.sub.2, or may arise spontaneously as does colon cancer in humans.
The phenomenon of viral oncolysis or the lysis of tumor cells by viruses with its resultant post-viral oncolytic immunity has been a subject of cancer research for approximately thirty years. One of the most notable contributions to this field is the work of J. Lindenmann entitled "Viruses as Immunological Adjuvants in Cancer", which appeared in Biochimica et Biophysica Acta, 355 (1974) 49-75. This article details the history of viral oncolysis from its inception in 1929 to 1974. Lindenmann has also reported that influenza A virus is capable of lysing transplanted Ehrlich Ascites cells in the peritoneal cavities of A.sub.2 G mice when injected directly into the tumor filled peritoneal cavity. The mice surviving the influenza oncolysis were noted to have developed post-viral oncolytic immunity and resisted rechallenge with the same tumor. Lindenmann, "Immunity to Transplantable Tumors Following Viral Oncolysis," J. Immunology, Vol. 92, pp. 912-919 (1964).
Asada injected mumps virus directly into tumors of patients with various kinds of terminal cancer and 25% of the patients showed some suppressed tumor growth, Asada, T., "Treatment of Human Cancer with Mumps Virus", Cancer, 34 (1907, 1974). Numerous other viruses have been injected into mammals bearing tumors to effect in vivo viral oncolysis. Among the viruses worked with are vesicular stomatitis virus, reovirus, mumps virus and West Nile virus. This technique, though promising, is difficult to apply in practice since most oncolytic viruses described in the art are harmful to man, and attempts to directly infect "in vivo" human tumor cells have yielded unsatisfactory results.
Attempts have also been made to stimulate the immune response of mammals to nonspecies-specific, transplantable tumors such as Ehrlich Ascites by preparing an in vitro viral oncolysate of influenza A or vesicular stomatitis virus prepared in suspension culture of Ehrlich Ascites cells. Mice immunized with the Ehrlich Ascites viral oncolysate were resistant to intraperitoneal challenge with living Ehrlich Ascites cells. Hakkinen et al., "Induction of Tumor Immunity in Mice with Antigen Prepared From Influenza and Vesicular Stomatitis Virus Grown in Suspension Culture of Ehrlich Ascites Cells", Journal of the National Cancer Institute, Vol. 46, No. 6, June 1971.
Bandlow et al have noted that vaccinia virus acts as an immunological adjuvant in the production of heterologous cytotoxic antibodies against host cell antigens and that guinea pigs show an increased cell-mediated immunity against host cell antigens after active immunization with vaccinia virus infected tissue culture cells. See Bandlow et al. "Untersuchungen zum Mechanismus der immunologischen Adjuvanswirkung des Vacciniavirus", Archiv fur die gesamte Virusforschung 38, 192-204 (1972) and "Increased Cellular Immunity Against Host Cell Antigens Induced by Vacciniavirus", Archiv fur die gesamte Virusforschung 45, 122-127 (1974).